Seeded schema mock data
Define typed fields, bounds, enums, uniqueness and null rates. Choose seed/count for repeatable synthetic JSON and configurable CSV.
- Runs in your browser
- No upload
- Check before download
Define typed fields, bounds, enums, uniqueness and null rates. Choose seed/count for repeatable synthetic JSON and configurable CSV. UUID-shaped values are not security tokens. Formula prefixing changes exported text.
Method: string / integer / decimal(0.001) / boolean / date(ISO8601) / uuid / enum / null
Local processing
Input stays in your browser worker, without requests, storage or content telemetry. Original backups and explicitly revealed exports may contain secrets; keep them local.
Resource limits
Combined input ≤1 MiB; text ≤200,000 characters (XML 100,000); depth 32 / nodes 20,000 per document; at most 1,000 rows/operations; output ≤2 MiB; worker deadline 5 s. Cancel terminates the worker. These application bounds do not guarantee a total browser heap cap.
1 to 50 fields × 1 to 1000 records, up to 50000 cells; the expected output is up to 1 MiB. Up to 100000 generation attempts, and 10000 per cell. Date minimum and maximum are whole days since 1970-01-01 (−719162 to 2932896); decimal step 0.001; strings use a–z; enums take one literal per line. Null is different from empty text, and exported null markers must not collide after formula prefixing.
Choose the profile and review diagnostics before using saved output. Editing, resetting or leaving cancels work and discards the preview. Save original backups separately; no source file is overwritten.
Original backup: 1048576 B / Inspect / generate
How to inspect this input
- Source
Define typed fields, bounds, enums, uniqueness and null rates. Choose seed/count for repeatable synthetic JSON and configurable CSV. UUID-shaped values are not security tokens. Formula prefixing changes exported text.
- Declared profile
string / integer / decimal(0.001) / boolean / date(ISO8601) / uuid / enum / null
- Review and save
Choose the profile and review diagnostics before using saved output. Editing, resetting or leaving cancels work and discards the preview. Save original backups separately; no source file is overwritten.
- Original backup
Input stays in your browser worker, without requests, storage or content telemetry. Original backups and explicitly revealed exports may contain secrets; keep them local.
Questions about the profile
Declared profile
Define typed fields, bounds, enums, uniqueness and null rates. Choose seed/count for repeatable synthetic JSON and configurable CSV. UUID-shaped values are not security tokens. Formula prefixing changes exported text. string / integer / decimal(0.001) / boolean / date(ISO8601) / uuid / enum / null
Local processing
Input stays in your browser worker, without requests, storage or content telemetry. Original backups and explicitly revealed exports may contain secrets; keep them local.
Resource limits
Combined input ≤1 MiB; text ≤200,000 characters (XML 100,000); depth 32 / nodes 20,000 per document; at most 1,000 rows/operations; output ≤2 MiB; worker deadline 5 s. Cancel terminates the worker. These application bounds do not guarantee a total browser heap cap. 1 to 50 fields × 1 to 1000 records, up to 50000 cells; the expected output is up to 1 MiB. Up to 100000 generation attempts, and 10000 per cell. Date minimum and maximum are whole days since 1970-01-01 (−719162 to 2932896); decimal step 0.001; strings use a–z; enums take one literal per line. Null is different from empty text, and exported null markers must not collide after formula prefixing.